The possible risks of submandibular gland tumor surgery are facial nerve injury, intraoperative bleeding, postoperative infection, and recurrence. 1. Facial nerve injury: Since the mandibular marginal branch of facial nerve is thin, submandibular gland tumor surgery can easily lead to injury, which may result in crooked mouth. 2. Intraoperative hemorrhage: the tumor may invade blood vessels, which will lead to blood vessel rupture and hemorrhage when peeling off the tumor during the operation. 3. Post-operative infection: after surgery, bacterial infection may occur in the surgical incision due to low resistance of the body or lack of cleanliness of the wound. 4. Recurrence: the chance of recurrence after submandibular gland tumor removal surgery is very low, but there is a possibility of recurrence. The risks of submandibular gland tumor surgery are mostly mentioned above, and you should go to the hospital for examination in time if any abnormal situation occurs.